Night Shift Work and Weight Gain Among Female Filipino Nurses
Interpretation of the Findings Evidence was found to indicate there were small positive associations between insufficient sleep and abnormal eating patterns with BMI among female Filipino nurses working the night shift. Because there was a small positive relationship between missed meals and BMI, the null hypothesis was partially rejected. In this study, it was determined that the average hours of sleep between shifts were 5 hours (n = 28, 42%), which showed moderate positive relationship with BMI (rs = .35, p = .004) and also indicated that there was a statistically significant association with BMI (rs = .25, p = .043); the most frequently missed meal was dinner (n = 33, 49%), which indicated that there were statistically significant associations of frequently missed meals with BMI (rs = .28, p = .024). The findings on insufficient sleep between shifts were confirmed with previous studies from Spaeth et al. (2013), who found that short sleep duration had associations with weight gain and increased BMI. According to Geiger-Brown et al. (2012), night shift workers had the shortest sleep duration between shifts compared to day shift workers that increased their risk of the weight gain that lead to an increase in BMI. The findings on quality of sleep were consistent with the previous studies conducted by Boughattas et al. (2014) and Vijayalaxmi et al. (2014), who reported that 60% of night shift workers’ sleep quality was severely compromised and 30% of them complained of insomnia. Also, Kim et al. (2015) found that even a single night of disrupted sleep influenced energy consumption and increased metabolism that promoted frequent eating and increased snacking on high calorie food. The findings on abnormal eating patterns were consistent with previous research from Spaeth et al. (2013), Griep et al., (2014), and Vijayalaxmi et al., (2014), who found that erratic eating patterns of night shift workers increased energy consumption that promoted increased snacking instead of eating a full meal, which was suggestive of metabolic imbalances that lead to weight gain. This study found that 12-hour shifts and the length of time working night shifts had significant associations with BMI. However, having worked extended hours beyond 12 hours did not show significant associations with BMI. The null hypothesis, therefore, can be partially rejected due to significant associations between night shift work and the number of years working a night shift with BMI. In this study, the variables of 12-hour shifts and extended years of working the night shift demonstrated statistically significant associations with BMI (rs = .30, p = .014). The research found (n = 63, 94%) that having continuous 12-hour shifts, and length of time working night shift showed nurses who have worked the night shift for 3-5 years (n = 20, 30%), and nurses who have worked for 21-35 years (n = 16, 24%), had statistically significant associations with increased BMI. In the findings on 12-hour shifts and number of years working the night shift, the significant associations with BMI were confirmed from previous research findings. For example, Kim et al. (2013) found that the longer the nurses worked on the night shift, the greater their risk of becoming overweight and obese. Also, Buss (2012) reported that weight gain was higher among night shift nurses. Other researchers have found that extended years of working the night shift caused health problems (Guo et al., 2013), such as hypertension, diabetes, heart diseases, some forms of cancer, and early disability (CDC, 2015). In addition, Gu et al. (2015) reported that for women who worked a night shift for an extended period of time, it
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significantly contributed to weight gain and increased BMI. Furthermore, Kim et al. (2013) found that long years of working the night shift demonstrated significant associations with increased BMI. Also, Vimalananda et al. (2015) found that African-American women who worked the night shift for long durations had significant associations with increased BMI. The ages of female Filipino nurses were found to have no statistical association with BMI. However, married participants had significantly higher BMI levels compared to single and divorced participants. Due to significant differences in marital status, the null hypotheses were partially rejected. In this study, no statistical relationship was found between age and levels of BMI (rs = .22, p = .069); however, the results of the ANOVA were significantly associated with BMI (F(3,63) = 7.08, p < .001. partial n2 = .252). This study’s results on age were not aligned with the previous studies from Letvak et al. (2013), who found that the age of older nurses is a factor that contributes to higher BMI compared to younger nurses. Contrary to the results of this study on age, Vimalananda et al. (2015) found that women younger than 50 years old were more likely to gain weight and become diabetic than those who never work night shifts. Likewise, Boughattas et al. (2014) reported that nurses’ ages influenced sleep quality and duration and were significantly associated with weight gain and changes in BMI. In this study, significant associations were found between marriage and levels of BMI. This result was confirmed in the previous research of Kim et al. (2013), who found that female married nurses were at a significantly higher risk of obesity and being overweight. Mata et al. (2015) found that married women had higher BMI than those who never married. No significant associations were found between stress, nursing units, and decreased physical activity with BMI among female Filipino nurses working the night shift in the hospital; therefore, the null hypothesis was not rejected. In this study, the analysis on perceived stress (rs = .03, p = .832), decreased physical activity (rs = .13, p = .289), and nursing units (F(4,62) = 2.33, p = 066, partial n2 = .131) failed to show significant associations with BMI among female Filipino nurses working the night shift in the hospital. These findings were not aligned with previous studies from Buss (2012), Vijayalaxami, George, and Nambiar (2014), Coomarasamy et al. (2014), and Han, Choi-Kwon, and Kim (2015), who found that stress and night shift work were strongly influenced by unhealthy eating habits causing weight gain. Many studies proved that physical activity has been identified as having tremendous benefits to overall health (Coomarasamy et al., 2014; Peplońska et al., 2014). Decreased physical activity is one of the many important factors that cause weight gain, being overweight, and obesity (Coomarasamy et al., 2014). The study findings failed to show a correlation between decreased physical activity and BMI among female Filipino nurses working the night shift.
Limitations of the Study This study has several limitations. First, due to cross-sectional design, the causality between occupational factors, such as night shifts, meals missed, working a 12-hour shift, quantity and quality of sleep, weight gain, being overweight, and obesity cannot be ascertained (Sedgwick, 2015). Second, this study completely relied on self-reported data, which may be
Journal of the New York State Nurses Association, Volume 46, Number 2
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